Messages in this thread Patch in this message | | | From | Adrian Hunter <> | Subject | [PATCH V2 16/23] perf intel-pt: Track sideband system-wide when needed | Date | Fri, 6 May 2022 15:25:54 +0300 |
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User space tasks can migrate between CPUs, so when tracing selected CPUs, sideband for all CPUs is still needed. This is in preparation for allowing system-wide events on all CPUs while the user requested events are on only user requested CPUs.
Acked-by: Ian Rogers <irogers@google.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- tools/perf/arch/x86/util/intel-pt.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c index 0ee93894a0da..06c2cdfd8f2f 100644 --- a/tools/perf/arch/x86/util/intel-pt.c +++ b/tools/perf/arch/x86/util/intel-pt.c @@ -864,20 +864,22 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, /* Add dummy event to keep tracking */ if (opts->full_auxtrace) { + bool need_system_wide_tracking; struct evsel *tracking_evsel; - err = parse_events(evlist, "dummy:u", NULL); - if (err) - return err; + /* + * User space tasks can migrate between CPUs, so when tracing + * selected CPUs, sideband for all CPUs is still needed. + */ + need_system_wide_tracking = evlist->core.has_user_cpus && + !intel_pt_evsel->core.attr.exclude_user; - tracking_evsel = evlist__last(evlist); + tracking_evsel = evlist__add_aux_dummy(evlist, need_system_wide_tracking); + if (!tracking_evsel) + return -ENOMEM; evlist__set_tracking_event(evlist, tracking_evsel); - tracking_evsel->core.attr.freq = 0; - tracking_evsel->core.attr.sample_period = 1; - - tracking_evsel->no_aux_samples = true; if (need_immediate) tracking_evsel->immediate = true; -- 2.25.1
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